Answer
$y=25$
Work Step by Step
The given equation is
$\Rightarrow 3\sqrt {y}-18=-3$
Add $18$ to each side.
$\Rightarrow 3\sqrt {y}-18+18=-3+18$
Simplify.
$\Rightarrow 3\sqrt {y}=15$
Divide each side by $3$.
$\Rightarrow \frac{3\sqrt {y}}{3}=\frac{15}{3}$
Simplify.
$\Rightarrow \sqrt {y}=5$
Square each side of the equation.
$\Rightarrow (\sqrt{y})^2=5^2$
Simplify.
$\Rightarrow y=25$
Check $y=25$.
$\Rightarrow 3\sqrt {y}-18=-3$
$\Rightarrow 3\sqrt {25}-18=-3$
$\Rightarrow 3\sqrt {5^2}-18=-3$
$\Rightarrow 3(5)-18=-3$
$\Rightarrow 15-18=-3$
$\Rightarrow -3=-3$
True.
Hence, the solution is $y=25$.
